Smokeless gunpowder.



UNITED STATES PATENT OFFICE.

CARL )LOF LUNDHOLM, OF STEVENSTON, SCOTLAND.

'SMOKELESS GUNPOWDER.

SPECIFICATION forming part of Letters Patent No. 701,591 dated 'June 3,1902.

Application filed February 28, 1902- To all whom it may concern:

Be it known that I, CARL OLOF LUNDHOLM, a subject of the King of GreatBritain, residing at Stevenston, in the county of Ayr, Scotland, haveinvented certain new and useful Improvements in Smokeless Gunpowders, ofwhich the following is a specification.

The present invention relates to smokeless gunpowders of the class whichare called nitroglycerin powders that is to say, powders which containnitroglycerin in a greater or less degree and nitrocellulose.

The introduction of nitroglycerin powders, which were first brought intonotice by Alfred Nobel about the year 1887, marked an era in the historyof propulsive explosives, for by the combination of nitroglycerin withnitrocellulose there were produced powders very much cheaper than thoseup till that time known, but, more important still, powders givingparticularly high velocities with low pressures, having exceedingly highenergy per unit of weight and a singularly high ballistic stability,together with a perfectly satisfactory chemical stability. The solepoint on which they have been found to be in any way inferior to thenitrocellulose powders is that the temperature of their explosion-gasesis higher and has been found to cause excessive erosion, especially inthe larger kinds of ordnance. Many attempts have been made to remedythis defect, some by mere reduction of the percentage of nitroglycerin,wh'ich, however, it carried to any considerable extent createsdifiiculty as to the removal of the last percentages of solvent, thuscausing ballistic instability. Other attempts have gone in thedirectionof varying the percentages of organic substances, with the object, amongother things, of increasing the percentage of carbon and hydrogen inrelation to oxygen, and thus reducing the temperature of theexplosion-gases. As examples of such additions may be mentioned biand'tri nitrobenzol, toluol, naphthalene, &c., organic esters, such asamyl succinate, cellulose, acetates, butyrates, &c., Vaseline, oxalateof ammoniaydsc. I have experimented with a large number of, substancesnot hitherto proposed, but all showed one defect or another. Y

After long investigation I have succeeded Serial No. 96,176. (Nospecimens.)

by the addition of diamyl phthalate in producingnitroglycerin-nitrocellulose powders which besides being cheap have allthe good qualities of their class in respect of high veloeit'y for lowpressure, while they have the advantage of giving a low heat and a highgas evolution.

As showing the relation of the improved nitroglycerin powders to thoseat present known I give the undernoted figures:

Ordinary cordite.

37 per cent. nitrocellulose 5 per cent. mineral jelly 58 per cent.nitroglycerin 1. Improved Nitroglycerin Powder.

30 per cent. nitroglycerin 60 per cent. nitrocellulose 5 per cent.diamyl phthalate 5 per cent. mineral jelly J 2. Improved NitroglycerinPowder.

80 per cent. nitrogl cerin 60 per cent. nitroce lulose 10 per cent.diamyl phthalate I have found the substance diamyl phthalate to be ofparticularly high chemical stability, and, as I have already mentioned,its use in these powders gives them particularly advantageous ballisticproperties without in any way detracting from their physical or chemicalstability. The substance can be added in any suitable way-for instanee,*by dissolving it in nitroglycerin or the volatile facilitating solventor adding it to the nitrocellulose. The powders are made in the same wayas the well-known ballistite and cordite. The proportions of the severalingredients used in these powdersmay be to some extent varied. I haveobtained very good powders from the following compositions:nitroglycerin, thirty; nitrocellulose, sixty; diamyl phthalate, ten, ornitroglycerin, thirty; nitrocellulose, sixty; mineral jelly, five;diamyl phthalate, five.

What I claim as my invention, and desire to secure by Letters Patent,'is-- 1. A smokeless gunpowder in which nitro- In testimony whereof Ihave signed my glycerin, nitrocellulose and diamyl phthalate name tothis specification in theiiresence of IO ai'qbeeolmbined, substantiallyas herein detwo subscribing witnesses. a sen I 5 2. Asmokeless gunpowderconsisting of ni- CARL OLOF LUNDHOLM.

troglycerin,nitrocellulose, mineral jelly and Witnesses:.diamylphtlmlate, substantially as herein de- ALEXANDER. FORBES,scribed. H. M. MURDOCK.

